Explanation of the problem

Due to heat, steel expands. Movable steel bridges may, when exposed to excessive heat, no longer open or close. In municipalities with movable steel bridges, this leads to problems on the road (when the bridge cannot close) or on the water (when the bridge cannot open). In the summer of 2018, this affected 70 bridges in Friesland alone at one point. In Amsterdam, 12 bridges remained closed, rendering two main shipping routes through the city impassable. The expansion of bridges poses a problem for transporters, (rail)road and bridge authorities, as well as users of (water)ways such as emergency services, the transportation sector, and recreational shipping.

Information and maps for better understanding

Basic maps according to the standardized stress test


Additional maps

  • Map showing the number of summer or tropical days now and in the future (Climate Impact Atlas) → provides an indication of the increase in problems related to the expansion of bridges.
  • Locations of movable bridges (Climate Impact Atlas) → to determine vulnerable areas.
  • Overview of critical infrastructure networks → identification of potential bottlenecks in transportation routes.

Some measures and guidelines

  • Cool bridges by keeping them wet with water sprayers (usually from surface water).
  • Modify bridges (grinding) to address expansion issues.
  • Ensure that alternative routes are available.
  • Design new bridges to be less susceptible to expansion.